The invention relates to pipe couplings in general, and more particularly to improvements in pipe couplings called quick connector assemblies which can be used to rapidly establish and rapidly terminate connections between pairs of pipes, tubes, hoses or nipples or between a pipe and another component such as a rod or the like.
It is already known to provide one component of a pipe coupling or an analogous coupling with a circumferentially extending external protuberance, e.g., in the form of a circumferentially complete bead. Such bead facilitates the establishment of a quick release connection between the beaded component and the other component. Reference may be had, for example, to U.S. Pat. No. 4,601,497 granted Jul. 22, 1986 to Bartholomew for "Swivelable quick connector assembly". The patented assembly employs a set of elastomeric arms having internal sockets for portions of the bead. The arms are confined in a sleeve which is in form-locking engagement with the arms when the assembly is in actual use, i.e., when the bead of a pipe extends into the sockets of the arms and the arms cooperate with the sleeve to prevent separation of the beaded component from the other component of the quick connector assembly. The patented assembly further employs one or more O-rings or analogous elastically deformable elements which sealingly engage the two components when the bead is properly received in the sockets of the arms. The arms have accessible end portions which can be flexed radially inwardly in order to disengage the arms from the sleeve and to permit extraction of the arms, together with the beaded component, from the interior of the sleeve. In other words, the beaded component cannot be separated from the sleeve and from the arms in a single operation; it is necessary to extract the beaded component jointly with the arms and to thereupon separate (if necessary) the arms from the extracted beaded component. This presents several problems; for example, the sealing element or elements which are confined in the sleeve must be prevented from escaping upon extraction of the beaded component and of the arms, and this necessitates the provision of one or more additional parts. Another drawback of the patented assembly is that separation of the arms from the extracted beaded component necessitates the exertion of a pronounced force which is likely to entail excessive deformation of the arms and/or of the part which couples the arms to each other. Separation of the arms from the extracted beaded component is necessary when the beaded component is defective but the arms and their coupling are intact or still in a condition which warrants their reuse in the patented assembly to separably connect a fresh beaded component with the sleeve and hence with a second component (such second component can be constituted by the sleeve alone or by a pipe or nipple which is preferably sealingly connected with the sleeve).
German patent application Ser. No. 31 29 522 of Schmidt (published Aug. 5, 1982 and corresponding to East German patent No. 0 154 393) discloses a pipe coupling which constitutes a modification of the quick connector assembly of Bartholomew. Schmidt proposes to confine an annulus of wedge-like locking elements in a sleeve which is axially movably connected to the housing of a check valve. The locking elements have internal sockets for the circumferentially extending external bead of a tubular member in the form of a plug. The latter can be pushed into the sleeve so that its bead penetrates into the sockets of the locking elements against the opposition of a spring which permanently biases the wedge-like external surfaces against the complementary internal surface of a hollow cone. The sleeve must be moved axially of the housing of the check valve in order to enable the locking elements to move apart and to thus permit extraction of the beaded plug from the housing. The pipe coupling of Schmidt comprises a substantial number of parts at least some of which must be finished with a rather high degree of precision. Moreover, and in order to move the sleeve in one direction with reference to the housing of the check valve, it is necessary to overcome the pronounced resistance of resilient means serving to bias the locking elements against the hollow cone and toward the axis of the sleeve.